import { Injectable } from '@nestjs/common';
import { generateShortId } from '../../common/utils/id.util';

export interface RecallQuestion {
  id: string;
  userId: string;
  knowledgeItemId: string;
  questionText: string;
  difficulty: string;
}

export interface RecallAnswer {
  id: string;
  userId: string;
  questionId: string;
  answerText: string;
  submittedAt: Date;
}

@Injectable()
export class ActiveRecallRepository {
  private questions: Map<string, RecallQuestion> = new Map();
  private answers: RecallAnswer[] = [];

  async findByUserId(userId: string): Promise<RecallQuestion[]> {
    return Array.from(this.questions.values()).filter((q) => q.userId === userId);
  }

  async findById(id: string): Promise<RecallQuestion | undefined> {
    return this.questions.get(id);
  }

  async createQuestion(data: Partial<RecallQuestion>): Promise<RecallQuestion> {
    const q: RecallQuestion = {
      id: data.id || generateShortId(),
      userId: data.userId || '',
      knowledgeItemId: data.knowledgeItemId || '',
      questionText: data.questionText || '',
      difficulty: data.difficulty || 'normal',
    };
    this.questions.set(q.id, q);
    return q;
  }

  async createAnswer(userId: string, questionId: string, body: any): Promise<RecallAnswer> {
    const answer: RecallAnswer = {
      id: generateShortId(),
      userId,
      questionId,
      answerText: body.answerText || '',
      submittedAt: new Date(),
    };
    this.answers.push(answer);
    return answer;
  }
}